{
volScalarField alphaEff("alphaEff",turbulence->nu()/Pr);

fvScalarMatrix TEqn
(
fvm::ddt(T)
+ fvm::div(phi, T)
- fvm::laplacian(alphaEff, T)
+ U.component(0)*gamma     //if your flow is periodic in y or z directions, e.g. component(1) or  //component(2).
);

TEqn.solve();
}
